Observation

Here is my 100% Achievement Guide for Observation (Including ALL 85 Collectibles)

If you are going for all collectibles in one playthrough, you will get this achievement regardless.

BUT, the actual location of it is, after you gain your Sphere upgrade on the station, you are tasked with going to EAS-11 to conduct your first "Spacewalk" (IE, go outside and float around in space).
As soon as you exit the airlock, stop, turn and go right a little, then go right again (Almost like a 360 degree turn) until you see a broken part of a ship.
This is EAS 12 Module, go towards it, tiny bit of debris to get past, but then go to the right once your inside, and there you will find Data Drop #15 (Collectible In My Suit, Heading Out) then as you exit, this achievement will unlock.

Go to 42:30 in my video to see the exact location.

Hope This Helps!

Thanks to BinkUncia from the playstationtrophies.org forum
(https://bit.ly/2VcDg3e)

This achievement is missable

This achievement is obtained once you are able to use the airlock controls in EAS-11 with your upgraded sphere as part of the story progression. Simply head to the right as soon as you start your "spacewalk" and fly towards the EAS-12 module which will be broken from the ship. When you reach this floating part, you need to manoeuvrer your way between the wreckage where you will find Data Drop 15. JR-EF-In My Suit, Heading Out and this is where the trophy should pop.